breacharbiter: simplify deps in BreachConfig fields + sweep incoming …

…htlcs

breacharbiter.go

@@ -43,9 +43,9 @@ type BreachConfig struct {
 	// it should respond to channel closure.
 	DB *channeldb.DB
 
-	// Wallet facilitates sweep transaction publication and further
-	// facilitates the generation of receiver scripts when sweeping funds.
-	Wallet *lnwallet.LightningWallet
+	// PublishTransaction facilitates the process of broadcasting a
+	// transaction to the network.
+	PublishTransaction func(*wire.MsgTx) error
 
 	// Notifier provides a publish/subscribe interface for event driven
 	// notifications regarding the confirmation of txids.
@@ -61,18 +61,19 @@ type BreachConfig struct {
 	// transactions.
 	Estimator lnwallet.FeeEstimator
 
-	// HtlcSwitch gives the breach arbiter access to shutdown any channel
-	// links for which it detects a breach, ensuring no further activity
-	// will continue across the link.
-	HtlcSwitch *htlcswitch.Switch
+	// CloseLink allows the breach arbiter to shutdown any channel links for
+	// which it detects a breach, ensuring now further activity will
+	// continue across the link. The method accepts link's channel point and a
+	// close type to be included in the channel close summary.
+	CloseLink func(*wire.OutPoint, htlcswitch.ChannelCloseType)
 
 	// Store is a persistent resource that maintains information regarding
 	// breached channels. This is used in conjunction with DB to recover
 	// from crashes, restarts, or other failures.
 	Store RetributionStore
 
 	// GenSweepScript generates the receiving scripts for swept outputs.
-	GenSweepScript func(lnwallet.WalletController) ([]byte, error)
+	GenSweepScript func() ([]byte, error)
 }
 
 // breachArbiter is a special subsystem which is responsible for watching and
@@ -232,10 +233,8 @@ func (b *breachArbiter) Start() error {
 			// notify the HTLC switch that this link should be
 			// closed, and that all activity on the link should
 			// cease.
-			b.cfg.HtlcSwitch.CloseLink(
-				&chanState.FundingOutpoint,
-				htlcswitch.CloseBreach,
-			)
+			b.cfg.CloseLink(&chanState.FundingOutpoint,
+				htlcswitch.CloseBreach)
 
 			// Ensure channeldb is consistent with the persisted
 			// breach.
@@ -558,7 +557,7 @@ func (b *breachArbiter) exactRetribution(
 
 	// Finally, broadcast the transaction, finalizing the channels'
 	// retribution against the cheating counterparty.
-	if err := b.cfg.Wallet.PublishTransaction(justiceTx); err != nil {
+	if err := b.cfg.PublishTransaction(justiceTx); err != nil {
 		brarLog.Errorf("unable to broadcast "+
 			"justice tx: %v", err)
 		return
@@ -692,9 +691,7 @@ func (b *breachArbiter) breachObserver(contract *lnwallet.LightningChannel,
 						"outputs with: %v",
 						spew.Sdump(sweepTx))
 
-					err = b.cfg.Wallet.PublishTransaction(
-						sweepTx,
-					)
+					err = b.cfg.PublishTransaction(sweepTx)
 					if err != nil {
 						brarLog.Errorf("unable to "+
 							"broadcast tx: %v", err)
@@ -726,7 +723,7 @@ func (b *breachArbiter) breachObserver(contract *lnwallet.LightningChannel,
 		// breached in order to ensure any incoming or outgoing
 		// multi-hop HTLCs aren't sent over this link, nor any other
 		// links associated with this peer.
-		b.cfg.HtlcSwitch.CloseLink(chanPoint, htlcswitch.CloseBreach)
+		b.cfg.CloseLink(chanPoint, htlcswitch.CloseBreach)
 
 		// TODO(roasbeef): need to handle case of remote broadcast
 		// mid-local initiated state-transition, possible
@@ -951,9 +948,19 @@ func newRetributionInfo(chanPoint *wire.OutPoint,
 	// it must sign and broadcast the justice transaction.
 	htlcOutputs := make([]*breachedOutput, nHtlcs)
 	for i, breachedHtlc := range breachInfo.HtlcRetributions {
+		// Using the breachedHtlc's incoming flag, determine the
+		// appropriate witness type that needs to be generated in order
+		// to sweep the HTLC output.
+		var htlcWitnessType lnwallet.WitnessType
+		if breachedHtlc.IsIncoming {
+			htlcWitnessType = lnwallet.HtlcAcceptedRevoke
+		} else {
+			htlcWitnessType = lnwallet.HtlcOfferedRevoke
+		}
+
 		htlcOutputs[i] = newBreachedOutput(
 			&breachedHtlc.OutPoint,
-			lnwallet.HtlcReceiverRevoke,
+			htlcWitnessType,
 			&breachedHtlc.SignDesc,
 		)
 	}
@@ -1002,9 +1009,19 @@ func (b *breachArbiter) createJusticeTx(
 	txWeight += 4*lnwallet.InputSize + lnwallet.ToLocalPenaltyWitnessSize
 	// Add to_remote p2wpkh witness and tx input.
 	txWeight += 4*lnwallet.InputSize + lnwallet.P2WKHWitnessSize
-	// Add revoked offered-htlc witnesses and tx inputs.
-	txWeight += uint64(nHtlcs) *
-		(4*lnwallet.InputSize + lnwallet.OfferedHtlcWitnessSize)
+
+	// Compute the appropriate weight contributed by each revoked accepted
+	// or offered HTLC witnesses and tx inputs.
+	for _, htlcOutput := range r.htlcOutputs {
+		switch htlcOutput.witnessType {
+		case lnwallet.HtlcOfferedRevoke:
+			txWeight += 4*lnwallet.InputSize +
+				lnwallet.OfferedHtlcPenaltyWitnessSize
+		case lnwallet.HtlcAcceptedRevoke:
+			txWeight += 4*lnwallet.InputSize +
+				lnwallet.AcceptedHtlcPenaltyWitnessSize
+		}
+	}
 
 	return b.sweepSpendableOutputsTxn(txWeight, breachedOutputs...)
 }
@@ -1046,7 +1063,7 @@ func (b *breachArbiter) sweepSpendableOutputsTxn(txWeight uint64,
 	// sweep the funds to.
 	// TODO(roasbeef): possibly create many outputs to minimize change in
 	// the future?
-	pkScript, err := b.cfg.GenSweepScript(b.cfg.Wallet)
+	pkScript, err := b.cfg.GenSweepScript()
 	if err != nil {
 		return nil, err
 	}